Improved prostate cancer detection using systematic 14-core biopsy for large prostate glands with normal digital rectal examination findings

Abstract

Objectives: To evaluate in a retrospective study the improvements in prostate cancer detection rates for patients with a prostate gland larger than 30 cm3 using a systematic 14-core biopsy strategy compared with a systematic 8-core biopsy.

Methods: We retrospectively assessed 273 patients with screened prostate-specific antigen (PSA) levels of 3.0 to 50.0 ng/mL. A total of 204 patients with a prostate volume of 30 cm3 or larger and with normal digital rectal examination findings were enrolled in this study. Of the 204 patients, 110 underwent 8-core biopsy and 94 underwent 14-core biopsy of the prostate. We compared the cancer detection rates of prostate biopsy between the 8 and 14-core groups using total PSA, free/total PSA ratio, PSA density, and PSA density adjusted by transition zone volume. We also analyzed the Gleason grade of the biopsy core and the radical prostatectomy specimens.

Results: Of the 204 patients, 40 (19.5%) were identified as having prostate adenocarcinoma. The cancer detection rate for the 8 and 14-core groups was 14.5% (16 of 110 patients) and 24.5% (23 of 94 patients), respectively. The 14-core biopsy had a statistically significant greater cancer detection rate than did the 8-core group in patients with a prostate volume of 30 to 40 cm3 (36.7% versus 11.8%, respectively, P<0.05) and a PSA density adjusted by transition zone volume of 0.38 ng/mL/cm3 or greater (47.8% versus 20.0%, respectively, P <0.05). The difference in tumor grade between the 8 and 14-core biopsy samples was not statistically significant.

Conclusions: The 14-core prostate needle biopsy is a recommended method for detecting prostate cancer in a large-volume prostate gland without increasing the risk of complications.